I wrote a challange and it didn't appear, then rewrote it many times and didn't appear. I'd like to know if there's something I did wrong or didn't do. I gave my user name, e-mail, season and then wrote the challange before I pressed submit.

I believe, but don't quote me, that Dia has to approve the challenges before they are posted. 

That is true. Challenges are not automatic, they must be checked first for suitability and  the only one who does that is DIa.  She is very busy with RL stuff right now; and, as she just posted a bunch of challenges not terribly long ago,  I would guess that it is not on her priority list ATM.  I'm sorry.

If you can't wait for Dia to get a chance to approve it, you could head over to the Challenge Spuffy LJ community and post your challenge there as well.

Thanks, guys! I'll wait for Dia then :)

And thanks Eowyn, I've posted my challenge there.